HLA-B and Genital ulcers: HLA-A*02:07 was associated with skin lesions (OR = 2.39, P = 0.002, Pc = 0.048) and arthritis (OR = 2.63, P = 0.002, Pc = 0.048), A*26:01 with uveitis (OR = 4.19, P < 0.0005, Pc < 0.012), and A*30:04 with vascular lesions (OR = 13.97, P < 0.00005, Pc < 0.0012), genital ulcers (OR = 3.89, P = 0.002, Pc = 0.048), and a positive pathergy test (OR = 5.87, P = 0.001, Pc = 0.024); the associations between HLA-A*26:01 and uveitis and between HLA-A*30:04 and vascular lesions were much stronger in HLA-B*51 negative patients than in total patients.